Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-19T23:01:57.625Z Has data issue: false hasContentIssue false

Myggbukta and Kap Broer Ruys: the most northerly of the East Greenland Tertiary igneous centres(?)

Published online by Cambridge University Press:  05 July 2018

B. G. J. Upton
Affiliation:
Department of Geology, University of Edinburgh, Edinburgh EH9 3JW
C. H. Emeleus
Affiliation:
Department of Geological Sciences, University of Durham, Durham DH1 3LE
R. D. Beckinsale
Affiliation:
British Geological Survey, Keyworth, Notts NG12 5GG
R. M. Macintyre
Affiliation:
Scottish Universities Research and Reactor Centre, East Kilbride, Glasgow G75 0QU

Abstract

The Myggbukta Complex is a shallowly dissected central volcano superimposed on the early Tertiary Plateau Basalts of NE Greenland. This, and the Kap Broer Ruys centre, 30 km to the east, appear to be the most northerly central complexes of the North Atlantic Tertiary Province. The Myggbukta Complex comprises a suite of extrusions and minor intrusions ranging from picritic basalt to potassic rhyolite: most of the suite appears related by relatively low pressure (< 10 kbar) crystal fractionation. A small rise in initial 87Sr/86Sr (0.70593) with silica content is attributed to minor contamination through crustal anatexis. A basic dyke-swarm associated with the complex, precedes it and shows more limited differentiation. The basalts of the dyke-swarm and the Myggbukta Complex are genetically intimately related to the lavas forming the upper part of the earlier plateau basalt succession (UPLS). It is proposed that a large shield volcano developed some 100 km west of the developing spreading centre (Mohns/Aegir ridge), of which the UPLS, the dyke-swarm and the Myggbukta Complex represent three successive evolutionary stages. A generalized increase in differentiation through time can be recognized from one stage to the next. The acid intrusions of the Kap Broer Ruys area are probably also largely residues of basalt fractionation like their Myggbukta counterparts. However, higher initial 87Sr/86Sr ratios (0.70625–0.71034) imply a greater degree of crustal contamination.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1984

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abbey, S. (1977) Geol. Surv. Can. Paper 77–34.Google Scholar
Beckinsale, R. D., Thompson, R. N., and Durham, J. J. (1974) J. Petrol. 15, 525-38.CrossRefGoogle Scholar
Bell, J. D. (1976) Proc. Geol. Assoc. 87, 247-71.CrossRefGoogle Scholar
Brooks, C. K. (1969) Geochim. Cosmochim. Acta 33, 357-74.CrossRefGoogle Scholar
Brooks, C. K. and Nielsen, T. F. D. (1982) Meddr. Gronland, Geosci. 9, 30.p.Google Scholar
Brooks, C. K. Pedersen, A. K., and Rex, D. C. (1979) Bull. Gronlands Geol. XJnders. 133, 28.p.Google Scholar
Brown, P. E., van Breemen, O., Noble, R. H., and Macintyre, R. M. (1977) Contrib. Mineral. Petrol. 64, 109-22.CrossRefGoogle Scholar
Carmichael, I. S. E. (1962) Mineral. Mag. 33, 86115.Google Scholar
Carmichael, I. S. E. (1964) J. Petrol. 5, 435-60.CrossRefGoogle Scholar
Dickin, A. P. (1981) Ibid. 22, 155-99.Google Scholar
Emeleus, C. H. (1982) In Igneous Rocks of the British Isles, Pt. 7, The Tertiary (Sutherland, D. S., ed.) Wiley, New York, 369425.Google Scholar
Gleadow, A. J. W., and Brooks, C. K. (1979) Contrib. Mineral. Petrol. 71, 4560.CrossRefGoogle Scholar
Lenz, O. (1874) In Die Zweite deutsche Nordpolarfahrt in den Jahren 1869 und 1870 unter Führung des Kapitan Karl Koldewey 2. F. A. Brockhaus, Leipzig, 481-96.Google Scholar
Meighan, I. G. (1979) Bull. Geol. Surv. G.B. 70, 1022.Google Scholar
Myers, J. (1980) Earth Planet. Sci. Lett. 46, 407-18.CrossRefGoogle Scholar
Nathorst, A. G. (1901) Forh. Geol. Foren. Stockholm. 23, 275306.CrossRefGoogle Scholar
Noe-Nygaard, A. (1976) In Geology of Greenland (Escher, A. and Watt, W. S., eds.) Geol. Surv. Greenland, Copenhagen, 386402.Google Scholar
Norrish, K. and Hutton, J. T. (1969) Geochim. Cosmochim. Acta. 33, 431-53.CrossRefGoogle Scholar
Orvin, A. K. (1931) Norsk, geol. Tidsskr. 12, 469-74.Google Scholar
Patchett, P. J. (1980) Nature. 283, 559-61.CrossRefGoogle Scholar
Rex, D. C., Glendhill, A. R., Brooks, C. K., and Steenfeldt, A. (1979) Rapp. Gronlands Geol. XJnders. 95, 106-9.Google Scholar
Saemundsson, K. (1978) In Crustal Evolution in Northwestern Britain and Adjacent Regions (Bowes, D. R. and Leake, B. L., eds.) Geol. J. Spec. Issue, 10, 415-22.Google Scholar
Sigurdsson, H., and Sparks, S. R. J. (1978) Nature. 274, 126-30.CrossRefGoogle Scholar
Speight, J. M., Skelhorn, R. R., Sloan, T., and Knapp, R. J. (1982) In Igneous Rocks of the British Isles, Part 7, The Tertiary (Sutherland, D. S., ed.) Wiley, New York, 449-59.Google Scholar
Sun, S. S. (1980) Phil. Trans. R. Soc. Lond. A297, 409-45.Google Scholar
Sweatman, T. R., and Long, J. V. P. (1969) J. Petrol. 10, 332-79.CrossRefGoogle Scholar
Thompson, R. N. (1982) Scott. J. Geol. 18, 48106.Google Scholar
Thorpe, R. S. (1978) Mineral. Mag. 42, 157-8.CrossRefGoogle Scholar
Thompson, R. N. Potts, P. L., and Sarre, M. B. (1977) Earth Planet. Sci. Lett. 36, 111-20.Google Scholar
Tyrrell, G. W. (1932) Geol Mag. 69, 520-7.CrossRefGoogle Scholar
Upton, B. G. J., Emeleus, C. H., and Beckinsale, R. D. (1984) J. Petrol. 25, 151-84.CrossRefGoogle Scholar
Upton, B. G. J., Emeleus, C. H. and Hald, N. (1980) J. geol. Soc. Lond. 137, 491-508.CrossRefGoogle Scholar
Wager, L. R., and Brown, G. M. (1968) Layered Igneous Rocks, Oliver and Boyd, London.Google Scholar
Walsh, J. N., Beckinsale, R. D., Skelhorn, R. R., and Thorpe, R. S. (1979) Contrib. Mineral. Petrol. 71, 99116.CrossRefGoogle Scholar
Walsh, J. N. and Clarke, E. (1982) Mineral. Mag. 45, 247-55.CrossRefGoogle Scholar
Walsh, J. N. Buckley, F. and Barker, J. (1981) Chem. Geol. 33, 141-53.CrossRefGoogle Scholar